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Jan, J.-S.

Publications and source records attributed to Jan, J.-S..

2 recordsLinked to original sources

Lab-on-a-chip device integrating a human stem cell-based blood-brain barrier model with neural organoids for translational research

For advanced biomedical research, complex, well-described human blood-brain barrier (BBB) models are crucial for studying central nervous system pathologies and brain targeting of nanotherapeutics. Our aim was to establish and characterize a complex lab-on-a-chip (LOC) system integrating a BBB model with neural organoids (NO). We optimized the conditions for BBB-NO models under static and dynamic circumstances. The combination of a human stem cell-derived BBB co-culture model with human midbrain organoids in a microfluidic LOC allowed the observation of BBB and neural tissue changes and the separate analysis of the barrier and brain units. The LOC design enabled phase contrast and fluorescent microscopy on the whole brain endothelial culture surface, barrier integrity and permeability measurements across the BBB model, and molecule passage into NOs. BBB-specific endothelial morphology, gene and protein expression, and good barrier integrity were demonstrated, corroborating the strength of the LOC engineering and cellular design. The transport of targeted nanoparticles across the BBB model followed by their entry to neural organoids validated the barrier integrity and transporter functionality of the dynamic integrated complex model. As a proof-of-concept experiment to confirm the translational value of the BBB-NO model integrated in the LOC device, we examined a clinically used hyperosmolar iodinated contrast agent, iopamidol, with confirmed neurological side effects. We corroborated that iopamidol induces transient BBB dysfunction and neural effects in the complex system, not only validating the complex dynamic BBB-NO model but also pointing to the necessity to study BBB changes together with NO functions.

cell biology↗

A small molecule cocktail for robust induction of blood-brain barrier properties

Blood-brain barrier (BBB) models derived from human stem cells are powerful tools to improve our understanding of cerebrovascular diseases and to facilitate drug development for the human brain. Yet providing stem cell-derived endothelial cells with the right signaling cues to acquire BBB characteristics while also retaining their vascular identity remains challenging. Here, we show that the simultaneous activation of cyclic AMP and Wnt/{beta}-catenin signaling, and inhibition of the TGF-{beta} pathway in endothelial cells robustly induce BBB properties in vitro. To target this novel interaction, we present a small molecule cocktail named cARLA, which synergistically enhances barrier tightness in a range of BBB models across species. Mechanistically, we reveal that the three pathways converge on Wnt/{beta}-catenin signaling to mediate the effect of cARLA via the tight junction protein claudin-5. We demonstrate that cARLA shifts the gene expressional profile of human stem cell-derived endothelial cells towards the in vivo brain endothelial signature, with a higher glycocalyx density and efflux pump activity, lower rates of endocytosis and a characteristic endothelial response to proinflammatory cytokines. Finally, we illustrate how cARLA can improve the predictive value of human BBB models regarding the brain penetration of drugs and targeted nanoparticles. Due to its synergistic effect, high reproducibility and ease of use, cARLA has the potential to advance drug development for the human brain by improving BBB models across laboratories. Significance StatementThe blood-brain barrier (BBB) hinders drug delivery to the brain and is implicated in neurological diseases. To better understand these processes in humans, there is a need for culture models that mimic the complexity of the BBB. However, state-of-the-art human BBB models either suffer from a non-physiological, mixed epithelial-endothelial identity or have weak barrier tightness, which greatly limits their usability. We identified a molecule combination that synergistically enhances barrier tightness in several in vitro models and induces complex BBB properties in human stem cell-derived endothelial cells by targeting a novel link between three signaling pathways. The molecule combination has the potential to improve BBB culture models across laboratories to advance both basic research and drug development for the human brain.

bioengineering↗